The present invention relates to methods and compositions for the use of compounds commonly known as amic acids to modify surfaces to provide benefits that may include hydrophilicity, soil resistance, and corrosion inhibition. Amic acids are commonly defined as compounds comprising one or more amide moieties and one or more carboxylic acid or carboxylate moieties.
In the context of this invention “soil resistance” is defined as imparting improved soil release properties to surfaces to facilitate subsequent cleaning. It applies to hard surfaces, particularly hard surfaces in domestic and industrial or institutional cleaning. It is common experience that oily or greasy soils and/or limescale soils, including soils made substantially completely of mineral deposits, such as alkali metal, particularly calcium and/or magnesium carbonates; and stains which include such mineral deposits combined with other soil such as water insoluble soap salts, for example, calcium and/or magnesium stearates, and with greasy or oily soils, can be difficult to remove from hard surfaces. In comparison, hydrophilic soils are usually easier to remove with aqueous wash systems. Accordingly it is particularly useful to treat hard surfaces to improve their resistance to oily or greasy soils and/or limescale soils. A further benefit from improving the soil resistance of hard surfaces is that it may reduce the tendency to form water tide marks and the tendency to leave streaks especially after rinsing.
The improvement in the soil resistance of substrates, especially hard surfaces, is important in that it reduces the tendency of soil material to adhere to the surfaces, in effect slowing the rate, or reducing the extent, of soiling and/or makes it easier to remove the soil when cleaning the surface, particularly by reducing the mechanical effort required to remove the soil.
In the context of this invention soil resistance also applies to textile surfaces, particularly to upholstered surfaces and carpets. The improvement in the soil resistance and particularly oily soil resistance allows oily soils to be readily removed from textile surfaces by traditional shampoo methods for these surfaces.
Treatments that provide corrosion resistance to surfaces, especially ferrous metal surfaces are useful in numerous applications. Non-limiting examples include inclusion in hypochlorite containing cleaning solutions, use in marine maintenance cleaners and protectants, temporary rust inhibiting compositions for storing or transporting cleaned metal parts, preventing corrosion in process water such as boilers and cooling systems, and preventing corrosion in equipment used to apply salts and brines to deice road surfaces.
The provision of a treatment that provides a hydrophilic property to surfaces is useful in many applications. In the cleaning and rinsing of for example, ceramic, glass, plastic, and metal surfaces a hydrophilic surface will cause the water to drain in a thin sheet with no water breaks, and reduce the formation of water spots and streaking when the surfaces are dried.
Amic acids, particularly those prepared from maleic anhydride copolymers and more specifically from styrene maleic anhydride copolymers are known. U.S. Pat. No. 6,232,405, to Schmidhauser, et al, discloses amic acids that are reaction products of styrene maleic anhydride copolymers and low molecular weight primary or secondary amines, that are useful as pigment dispersants for inks. Preferred amines possess 4 carbon atoms or less. Dimethylaminopropylamine, which contains 5 carbon atoms, is mentioned. The amic acids that are disclosed to be useful as pigment dispersants are derived from methyl amine and ethyl amine.
Other reaction products of maleic anhydride copolymers with compounds containing both primary and tertiary amine functionality are known. U.S. Pat. No. 4,065,608 to Beck, et al, discloses a process of preparing a cationic paper sizing agent that is a copolymer of maleic anhydride and an alpha olefin containing 10 to 26 carbon atoms, reacted with mono primary/mono tertiary alkylene diamines and then further reacted with a low molecular weight polyamine. The process is carried out in an organic solvent and water is removed; the product is therefore an imide and not an amic acid.
U.S. Pat. No. 3,432,479 to Verdol, et al, discloses reaction products of a copolymer of a vinyl compound and maleic anhydride with monoamine and a polyamine, which can be a mono primary/mono tertiary amine. Again the reaction is carried out under conditions that produce the imide rather than the amic acid. Verdol's compositions are oil soluble and useful as detergents in lubricating oils. U.S. Pat. No. 5,391,636 to Schilling discloses corrosion inhibiting compositions for metals in highly acidic environments which are polyimidoamines produced by the reaction of mixtures of styrene maleic anhydride copolymers and rosin or rosin derivatives, or fatty acids, or fatty acid derivatives, with one or more polyamines. The reactions are carried out under conditions that produce the imides.
U.S. Pat. No. 5,759,485 to Fischer, et al, discloses imidazoline and amidoamine salts of C22 tricarboxylic acids useful as corrosion inhibitors. The tricarboxylic acids are formed by reaction of C18 unsaturated fatty acids with maleic anhydride or fumaric acid or mixtures thereof. The resulting Diels-Alder adducts are first hydrolyzed with water to carboxylic acids before neutralizing with the amines and thus are salts and not amic acids.
There are many polymeric, film forming, hydrophilic compositions disclosed that are claimed to be useful as soil release treatments for hard surfaces and textiles. U.S. Pat. No. 8,709,168 to Waite, et al, discloses quaternized polyethylenimine polypropoxylate polyethyoxylate polymers. Because they are cationic they are not compatible with anionic surfactants, which are very commonly used in cleaning formulations.
U.S. Pat. No. 6,569,261 to Aubay, et al, discloses polymers that confer hydrophilic properties and corrosion resistance to glass and ceramic materials. The polymers are copolymers of “diquat”, (a methacrylamido propyl monomer that contains 2 quaternary ammonium moieties), monomers with anionic functionality, and optionally hydrophilic monomers with neutral charge, in molar ratios of cations to anions preferably between 60 to 40 and 20 to 80.
U.S. Pat. Nos. 6,767,410 and 6,593,288 to Aubey, et al, disclose polymers that confer long lasting hydrophilic properties to hard surfaces. The polymers are copolymers of preferably diallyldimethylammonium chloride, monomers with anionic functionality, and optionally hydrophilic monomer with neutral charge, in molar ratios of cations to anions preferably between 50:50 and 10:90.
U.S. Pat. No. 6,703,358 to Aubey, et al, discloses cleaners for hard surfaces that contain at least one surfactant and a copolymer of preferably methacrylamidopropyltrimethylammonium chloride, monomers with anionionic functionality, and optionally hydrophilic monomer with neutral charge, in molar ratios of cations to anions preferably between 25:75 and 70:30.
U.S. Pat. No. 7,902,141 to Becker, et al discloses a hard surface treatment comprising a compound that is the reaction product of a polyamine, a crosslinking agent, and a component that contributes carboxylic acid, amide, nitrile, or ester functionality. The compositions are useful for example as hard surface treatments to prevent the formation of water spots and the adhesion of lime soap soil.
U.S. Pat. No. 7,741,265 to Iverson, et al, discloses a cleaning composition for hard surfaces that provides a hydrophilic barrier coating. The compositions comprise a nonionic surfactant, an acid, and a polymer with an acidic monomer capable of forming an anionic charge and a monomer having a permanent cationic charge or capable of forming a cationic charge upon protonation. The compositions have a pH value between 2 and 3.5 and do not contain surfactants with ionized moieties.
U.S. Pat. No. 8,410,038 to Davister, et al, discloses a cleaning composition containing an organic acid and a nonionic surfactant, and a hydrophilic polymer that absorbs to hard surfaces. Many polymers are described broadly including cationic polymers, amphoteric polymers, anionic polymers and betaines. The claims include only betaines and the structure is not further described.
U.S. Pat. No. 8,641,827 to Blattner, et al, discloses hard surface cleaners comprised of alkyl polyglucosides, glycerine, and cationic surface modification polymers described as polyampholytes with an acidic monomer capable of forming an anionic charge and a monomer having a permanent cationic charge or capable of forming a cationic charge upon protonation, and discloses that suitable polymers are described in U.S. Pat. Nos. 7,741,265, 6,569,261, 6,593,288, 6,703,358, and 6,767,410, described above.